The clinical and immunologic responses of patients with insect sting anaphylaxis will be monitored and correlated. The clinical results will be evaluated by the effects of inadvertant stings or planned stings under observation. Venom-specific IgE and IgG will be measured in sequential serum samples. The effects of time alone and of specific venom immunotherapy will be determined. Specific problems to be addressed include mechanisms of insect sting allergy and immunity, the amount and duration of immunotherapy, and the natural history of insect sensitivity. Similar clinical and immunologic data will be applied to the studies of the natural history of large local reactions following insect stings and the indications, if any, for specific immunotherapy. The purity and potency of vespid (hornet and yellow jacket) venoms obtained by electrical stimulation and "washing" of venom sacs will be compared. Yellow jacket and hornet venoms will be fractionated and the antigenic and allergenic components isolated and identified. These fractions will be used for studies of the cross-antigenicity between vespid venoms. The IgE and IgG antibody responses of honeybee-sensitive patients to purified bee venom fractions, phospholipase A, hyaluronidase, mellitin and acid phosphatase will be measured and correlated to clinical allergy and immunity. Bee venom will be modified by a variety of methods in an attempt to prepare a "venomoid" which will stimulate IgG production with decreased IgE binding.